The invention relates to a thrust washer for an electric machine for arranging on a shaft between a bearing and a rotor, preferably a rotating electric contact element, which is influenced by brushes, or rather a laminate stack of the rotor, wherein the thrust washer comprises a region for providing a sealing arrangement with two end faces, and at least one radial contacting section for the bearing and the rotor respectively is provided on each end face. A thrust washer of this type for an electric machine can be arranged on a shaft between a bearing and a rotor, in particular between a rotating electrical contact element, which is influenced by brushes, or rather a laminate stack of the rotor. The thrust washer comprises a region for providing a sealing arrangement with two end faces and has on each end face at least one contacting section for the bearing and/or the rotor.
Electric motors such as those generally used for heating and air-conditioning motors are required to fulfill stringent requirements with regard to noise. The noise level of said electric motors is greatly influenced by the so-called longitudinal oscillation of the armature that is excited by way of the longitudinal play of generally a few one-tenth millimeters that occurs in the electric motor during operation. So-called thrust washers are located in the electric motor and are arranged between the non-moving bush bearings and the rotating armature or rotor and said thrust washers by virtue of their material characteristics such as wear-resistance, surface, serviceable life etc.—reduce the friction. As a result of the likewise high requirements for a long serviceable life, in other words good wear resistance, the material, generally an elastic synthetic material, for example polyester elastomer, has a comparatively small amount of intrinsic elasticity. It is also known to install corrugated washers or corrugated rings. However, corrugated washers or corrugated rings only function when in contact between the non-moving parts and the rotating parts.
It is possible by means of skillful selection of the elasticity and damping of the thrust washer to modify the excitation of the axial oscillation to such an extent that said axial oscillation is damped during operation and thus does not cause any noise production. DE 10 2004 044 340 A1 discloses for example a thrust washer of the type mentioned above for an electric machine, in which the contacting sections of the two end faces are mutually connected by way of resilient sections that are embodied on the thrust washer.